1. Field of the Invention
The present invention relates generally to devices and methods for cutting soft tissue. More specifically, devices and methods for a minimally invasive procedure for cutting or excising a volume of soft tissue such as a biopsy or a therapeutic excision of cancer are disclosed.
2. Description of Related Art
Minimally invasive procedures have instigated a need for refinement in surgical devices that can function within confined spaces, particularly in soft tissue, such as breast tissue. Devices that are typically used during open surgical procedures (i.e., scalpel, scissors, electrosurgical “pencil” electrode) are often not adaptable for use in a minimally invasive procedure. In addition, the actual procedure cannot be directly visualized as the skin incision is typically just large enough to insert the device. Minimally invasive procedures are often guided by medical imaging or by video camera as is often used in laparoscopy. In the breast, mammography, ultrasound and magnetic resonance imaging (MRI) are used to guide minimally invasive procedures. Current devices that use an oscillating sharp edge or radio frequency energy to cut the tissue retrieve a specimen of fixed volume and are not adaptable to excise lesions of different sizes or include extensions of the lesion or disease process in the excision. In particular, breast cancer often extends towards the nipple within a milk duct or towards the skin in Cooper's ligament in addition to growing outward in a radial direction. Current minimally invasive devices are designed to excise a mass and are not adaptable for excision of an associated diseased duct or Cooper's ligament. Leaving cancer behind in the duct or in Cooper's ligament increases the risk of local recurrence despite the administration of post operative radiation therapy.
Open surgical biopsy removes lesions of variable size and may include extensions of the lesion but often an excessive amount of normal breast tissue is included in the specimen leading to a poor cosmetic result. In addition, open surgical biopsy typically requires a significant skin incision resulting in a longer, permanent scar. More importantly, a diseased duct and/or disease in Cooper's ligament are not detectable either by direct vision or by palpation during an open surgical procedure. The main cancerous mass may be excised, but a diseased duct filled with cancerous cells and/or diseased Cooper's ligament is often not appreciated during the procedure and unintentionally not included in the excision.
Axial ductal ultrasound is a method of ultrasound scanning of the breast that demonstrates the internal anatomy of the breast. In particular, the ducts and lobes of the breast are identified resulting in visualization of not only a lesion, but also diseased duct(s) and extension into Cooper's ligament. Multifocal cancers or additional cancers associated with the diseased duct may also be visualized. Therefore, the entire disease process (i.e., the lesion and extensions of the lesion within the breast) is visualized and can be removed under direct, real-time ultrasound guidance.
Accordingly, there is a need for a device and method for a minimally invasive procedure that excises lesions of variable size within a volume of tissue from a breast or other soft tissue. More specifically, there is a need for a device and method to excise a disease process within a breast that includes not only the main focus of the disease (i.e., a lesion or a mass) but also the duct or ducts that are also affected and any other anatomic extension of the disease process (e.g., growth into Cooper's ligament). Preferably the procedure is guided using medical imaging.